


TIME TO SIN

by MissKierie



Category: Undertale (Video Game)
Genre: Alternate Universe - Horrortale, Alternate Universe - Underfell, Biting, Blindfolds, Blood, Bondage, Breeding, Cum Inflation, Daddy Kink, Dirty Talk, Dom Sans, Ecto-Penis, Ecto-Tongue, Exhibitionism, F/M, Hair-pulling, Horror, Impregnation, Inflation, Knifeplay, Masochism, Mildly Dubious Consent, Multiple Orgasms, Oral Sex, Other, Outdoor Sex, Overstimulation, Rape, Rough Sex, Sadism, Sensory Deprivation, Skeletons, Sweat, Underfell Sans, Vaginal Sex
Language: English
Status: In-Progress
Published: 2016-03-31
Updated: 2017-01-09
Packaged: 2018-05-30 09:45:39
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings, Graphic Depictions Of Violence
Chapters: 4
Words: 8,481
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6418885
Author URL: https://archiveofourown.org/users/MissKierie/pseuds/MissKierie
Summary: <blockquote class="userstuff">
              <p>A collection of random excerpts and requests. All of them SMUT.</p>
            </blockquote>





	1. Chapter 1

**Notes for the Chapter:**

> a request for Underfell Sans in a dominant heat. i dont like the concept of characters being in heat, so i kept it vague. these two characters discussed consensual non-consent, including initiating sex while unconscious, before this scene.
> 
> gender neutral reader who has a vagina.
> 
> Underfell Sans: http://kierie.tumblr.com/post/141044576090/i-love-him

It smells like a damp, autumn evening. Fresh rain, piles of leafs, burning wood. The moosh of plant waste below your shoes. Walking down an empty, suburban street. Carefully tight-walking the right curb. It’s drizzling. This is a dream. But you don’t know that. Jostled around by what feels like a blustering wind. The way it caresses your now nude buttocks feels way too real. Gentle brush of fabric against your face. Attempt to reach up to scratch at the sensation, only to find your arms paralyzed. Stop and tumble over the curb, causing your leg to kick in the waking world. It’s not enough to wake you, but the feeling of a warm cock piercing you sure does.

Thrown into a panic as the stretch from the foreign penetration burns your unprepared muscles. Open your mouth to scream and you’re flooded with the taste of sweat as familiar phalanges shove inside. It’s him.

“Saaahns,” you whine against his fingers as his member pumps into you once, twice, with unexpected ease. Blink blink, find only darkness. Blindfolded? Lying on your stomach, hands restrained behind you, back forced to arch dramatically from one skelehand death-gripping your hip.

So wet, can tell there’s added artificial lubrication along with his ecto saliva. Struggle against what feels like rope only to have him snarl behind you, leaving your mouth to grasp your scalp and smash your face into the mattress.

“Saa-!” “shut tha **FUCK** up, (your name).”

His voice is so low and sordid, hands grasp and tremble with palpable desperation, immediately you can tell what’s going on. He must be-

Train of thought is severed as he growls into you enough to rattle your bones, his hips starting a breakneck pace. Moan lustily into the sheets as your body begins to not only endure, but savor his pummeling. Try to turn your head enough to alleviate the compression of your nose. Any movement other than spreading your legs and meeting his thrusts makes him hiss and press you even deeper into the bed.

“Sans,” you manage to utter, voice muffled.

“shuddup, **shuddup** ,” he froths, taking a fistfull of hair, yanking you up, only to mash you back down, “just shut tha fuck up fer fuckin’ once, you fuckin’ son of a-nnnaah, ha aaah.”

It’s so fast, oh god, oh god, curl your fingers with little feeling in them, the tight restraints already cutting off blood flow. Heated perspiration drips on your back. Unable to see or change position, your awareness concentrates on the thick member pounding relentlessly, the jut of bone every time he hilts, the stale scent of the unwashed linen, the wet noises of your union, and Sans’ almost hysteric ramblings.

“fuckin’ fuck, yer cunt feels so fuckin’ _gooooood_ , baby.”

Just when the level of forced arousal in your body rises to a genuinely delicious state, the monster behind you climaxes, one hand gripping your hip enough to draw blood, the other raking sharp distals down your back. The heat of your skin opening is overpowered by the scorching seed he fires into you. The magic tingles and nearly numbs your insides as it fills every crevasse it can before leaking down your thighs.

The first time this happened you thought one orgasm, done, all better right? You know better by now. Sans flutters behind you, mumbling a few more things as his throbbing member moves a few more times, then leaves you completely. Clench your muscles to hold as much of his gift inside you as you can. 

Seemingly indifferent to your effort, both hands manhandle you until you lie on your back, new pain surfacing from the fresh cuts grinding into the mattress, arms crushed under your weight. 

Familiar spark of magic circles your ankles and spreads you at a merciless angle. The same force prevents your head from doing anything other than facing the ceiling. Now the only thing you can move are your hips, which you buck upward when an almost gelatinous appendage slides up your swollen folds. Recognize that it’s a tongue when his torrid breath blasts your crotch. It dives inside and scoops out what it can as his hands wander your body, fluctuating between leaving surface lacerations and pawing at supple curves.

You wish you could see the absolute need on his face, but the blackness covering your eyes deprives you of that luxury. Concentrate on your other senses and use your imagination to fill in the blanks. God, his tongue, his fucking tongue, you love it.

“fuck, (your name), i want ya ta cum, i wanna taste ya, fill my mouth ya fuckin’ slut,” he huffs, shoving two phalanges back into your mouth when you try to respond to his frenzied dirty talk. Fingers fuck your face, flattening your tongue and carefully sliding down your throat until you gag. “oooh babe, just lookit ya. fuck, yer my good lil’ toy, aren’t ya?” Release garbled moans around his digits, tunnel clenching around him, pelvis rocking into his face.

Both hands move to your genitals and you suck in much needed oxygen, but it’s set free straightaway when skelethumbs pull your clitoral hood back, exposing the entirety of the delicate erogenous zone. The groove of his flat tongue surrounds it, assaulting it with rapid, feather-like strokes while the rest of the appendage continues to fuck your now pulsating entrance.

“YESSS,” you finally respond, hips continuing to buck with wild abandon, the peak of your sexual high quickly approaching. The tips of a few fingers squeeze into the space around his tongue, slipping past the first few inches of muscle, then curl, pulling, stretching you open until you scream that it’s too much.

“too much, huh? too fuckin’ much? fuckin’ _good._ ”

Whenever he gets like this he loves flirting with the edge of your limits. Teasing them just a bit, pushing you further and further almost every time. Can’t decide if you hate it or love it. Maybe a bit of both.

Applies more pressure to the nerve bundles at your crest and inside. The urge to urinate mixes with your teetering arousal and you completely let go. Clitoris enlarges with blood and you can hear him rumble happy as he drinks your orgasm, tongue and fingers vacating to allow your juice to flow. Everything is so vivid as you ride it out, each electrical signal blurring reality until you lose the ability to process anything other than sexual stimulation. Continual laps at your folds for a few minutes as you just breathe and listen to the thump of his hand hitting the bed below you. Must be jacking off.

Springs complain and you bob lightly as Sans plops down somewhere on the mattress. Fizzles of magic encase and lift you until femurs touch the bottom of your thighs, calves tucked under him. Probably sitting in his lap. Dizzy from the orgasm and lacking the added balance of untied arms, you wobble, falling forward against him. He’s so wet from perspiration, so musky, bones as feverish as ever. It all screams I need more

There’s a pssh pssh sound of a bottle being pumped and then a hand adding lubrication to your recovering vagina. Round 2. Drumming heat against your orifice, circling once, twice. His magic releases your body, causing gravity to impale you on his member. Quiver against him as he groans, thrusting into you even faster than before. Stops, panting heavily.

“ok ok…” he drawls, “phew, ah, ok. ride me, sugartits, c’mon.” He emphasizes the pet name with a rough kneading of your breasts, mooshing the tissue across your chest, covering you with whatever lube he’s using. Can tell he’s holding back, trying not to completely destroy you.

Twist your ankles to move your feet into a more stable position, lean into his hands, flex your rectus femoris and start bouncing. Lift and lower yourself, giving his pelvis a thorough grind every time he fills you. The points of his pelvis poke and prod and that just makes you appreciate your otherworldly lover so much more. 

Fingers move around your torso to the now scabbing wounds of your back to reopen them, phalanges digging, new red flowing. “Rub my clit,” you rasp, throat dry from breathing heavily, “make me cum for you again.”

He obliges, gliding ridges across the distended organ, other hand slowly pulling open the skin of one gash. 

It all feels so good and overwhelming, the flooding neurotransmitters deactivate your common sense and you whisper, “I know you’re holding back. Don’t. Use me, bite me, fucking-aaA **AH!!** ”

Teeth delve into the taut skin of your sternum and you scream as his jaw clenches, the sound of splitting tissue accompanying the squish of your sex. IT HURTS. He uses that skin like a handle, yanking you towards him as his pelvis resumes it’s previous onslaught. “like that, babe? ya like that? whadda fuckin’ freak,” his words reverberate into your rib cage, “ya fuckin’ love this shit. i can’t fuckin’ believe ya sometimes.”

Jaw unhinges and teeth leave your chest to sink into a large portion of your shoulder, closing until bone almost meets bone. Oh god, it fucking HURTS. Blood runs down your body and joins the lubrication between your legs. Neither of you care. “MORE, fuck, I’m gonna-! _Come on!!_ ”

“i can’t believe ya actually fuckin’ exist. shit, yeah, take it, take it **all**. yer all _mine_ , angelface, all fuckin’ mine.”

Sans’ mouth withdraws again and the thrusting of his cock and the stimulation on your clit brings you to another climax. Much less liquid than before squirts onto him and you just grind into his lap, throwing your head back with a dramatic squeal. Your euphoria is cut short when a part of him collides with your chest, hitting you with enough power to knock you back. 

Panic rushes as you don’t find a bed to catch you and instead you fall for what feels like an exorbitant amount of time. Land on the hard floor, legs still propped on the edge of the bed. There’s a crack from your arms upon landing on them and you’re so grateful you lost all feeling in them already. It reeks of dirty laundry and stagnant water down here. Hands circle your lower back and lift you. You’re hoisted enough so only your head and shoulders touch the floor, the rest of you suspended by Sans. Spine arches unpleasantly as the weight of your arms pulls you in the opposite direction. Now the only thing you can smell is blood.

Cock pushes into your now puffy entrance, making you cry out, you’re so sore. Round 3. “heh heh,” he chuckles, “yer getting loose, (your name).”

Twist up your face at his words. Is this asshole complaining? What the fuck does he expect, he’s been using the same hole non-stop lately. Hands release and you levitate in thin air, his magic on your soul keeping you in place. He moves your legs and crosses them tightly, tossing them over what feels like a shoulder. The new position increases your clench around him tenfold. Arms hug around your limbs and push against them, each thrust of his dick reaching deeper and deeper.

“mmn, thaz better.” Whimper unhappily at him, pussy burning despite the generous lubrication. “that hurt, human? heh, ya already look so fuckin’ broken. iz adorable.”

He fucks you like that for a while. The pain eventually fades into almost numbness. More of his seed shoots inside, which doesn’t even make him pause. Constantly asks you if you’re going to cum and each time you say no. Not even close. That only frustrates him and seems to fuel his determination. Manages to extract one more painful orgasm from you with ridiculously fast thrusts. It makes you cry and beg for him to stop. He does.

Brings you to the bed. Undoes the rope around your wrists. The incredible pain of blood rushing back into them makes you cry again. Removes your blindfold. Everything’s too bright and vivid, you just close your eyes as he proceeds to clean you with his tongue, roughly jacking his still throbbing magic the whole time. Lift your lids enough to see his mesmerized expression as he just. looks at you. He needs more. And he’s still holding back.

Have some spaghetti and fall asleep in his soiled bed. No dream this time. But you are woken up again to a desperate skeleton entering you. Back hole this time. Okay. Next round. You can do this. For him.

Okay. Maybe a little bit for yourself too.


	2. Pushing Your Buttons

**Summary for the Chapter:**

> A date with UT!Sans ends in a way you don't except after a bit of subtle flirting on your end.

**Notes for the Chapter:**

> a commission, Daddy kink.
> 
> female identifying reader who has a vagina.

This was… what, your fifth date with Sans? That sounds about right. 

Grillby’s again, for dinner. You rolled your eyes at his invite but was still all kinds of excited to see him again. The short skeleton was a lot of things, but above all else he was fucking _cute_. His jokes, the way he would watch you, and how much he blushed whenever you got him flustered. Which wasn’t very often, but that made it that much more rewarding.

You were both adults and already had sex several times by the time this ‘official date’ came around. He was lazy in the sack more often than not, but also surprisingly kinky. Pressing just the right buttons tended to make him more active and aggressive. 

That’s what you’re doing right now. Sitting next to Sans at the bar, sipping your drink, and trying to press a few buttons without blowing your cover. A lingering glance, casual touching, spreading your legs a little too much when changing positions. If he noticed, he wasn’t letting himself react to it. Except for a slight dilation of his illuminated pupils now and then.

“i swallowed two pieces of string earlier, and they came out tied together,” Sans says out of nowhere.

You make a funny sound into your drink, pull it away and wipe the stickiness from your chin, “ _What??_ ”

“i shit you _knot_ ,” he sneers, eyes lidded, grin as crooked as ever.

After a few playbacks in your head, the joke hits you, and you nudge him roughly with your elbow. “Pfft, that’s so stupid. You’re a skeleton, for pete’s sake.”

“how do you know what i’m _capitate_ of?”

It’s a skeleton joke, but you don’t know what bone that is, so you ask.

“this one,” he clarifies, pointing to one of the longer bones in his wrist, “haven’t you learned the entirety of my anatomy, yet? shame on you.”

Snort into your glass, your voice echoing lightly as you speak into it, “sorry, _dad_. Please don’t ground me! I’ll study harder, I promise.” Down the rest of your beverage and when you place the cup back down, Sans is. looking at you. in _that_ way. For just an instant, then it’s gone.

He fiddles with the bottle of ketchup on the counter, gaze returning to normal, save a bit extra smugness. “if you were my kid,” his voice darkens, “ya’d know better than to tease daddy in public.”

 **Oh.** Did he just… 

Yeah, he did. Eyes widen and your face flushes with color, throat suddenly feeling dry. Fuck, daddy kink? You haven’t even told him about that one yet, how did he know? Come on, think about it, he didn’t know. He was just testing you, seeing if he can push one of your buttons. And he totally fucking did. 

Clear your throat and speak up, trying to sound in control, “tease you? Don’t you think you’re being a little dramatic?” You push right back, invading his personal space to pick a piece of lint off the leg of his shorts. 

In a hushed voice, he responds, “you’re gonna be in trouble if you play this game with me, lil’ girl.”

 **Ooh.** In trouble. That sounds like fun~. Lean in, chest rustling the sleeve of his jacket, lips brushing his skull, and you whisper, “try me, _Daddy_.”

You can’t breathe or move. His magic has ahold of your soul, gripping, and suddenly there’s a warm pressure against your panties. Sans opens his eyes slowly, his single cyan iris large and focused on you. “you’re gonna go to the bathroom,” he utters, phalanges tapping one after the other on the counter, “the last stall. you’re going to take off your panties and wait for me.”

Gasp in air when his hold releases, heart pounding, holding in a whine when the magic between your legs pushes at your concealed entrance. 

“go,” he instructs.

And you do. Legs a bit shaky, you stand up and walk through the kitchen doors on the left, down the hall, and into the ladies bathroom on the right. Grillby’s is fairly quiet tonight, it is Tuesday evening, so it’s pretty empty. Last stall. Close the door behind you and pull up the skirt of your dress to pull your panties down.

Before they even get past your knees, familiar hands are upon you, wrapping around your neck, groping the fat of your asscheek. Sans exhales loudly, the end of it transforming into a growl as he gives you a solid **_WHAP_**. His metacarpals silence you before you can even get a sound out, gripping your throat tight enough cut off the intake of oxygen briefly.

“you naughty lil’ brat,” he grumbles next to your ear, spanking you again before moving to fondle your crotch. You’re still wet from making out with him before dinner and this sudden, wolfish behavior of his isn’t helping. “you know _exactly_ what you do to me. you know exactly how much i want you, how hard you make me.” The evidence presses against your outer thigh. He humps against you lightly, so warm, you can feel him throb through his shorts, fuck.

So flustered, you aren’t even sure what to say. “I’m sorry, Sans.”

His hand reels back and comes up between you legs; the slap, loud and wet against your pussy. “i’m not your boyfriend right now, sweetheart. you need to be punished and your daddy is in charge of that.” He slaps you again, harder, and groans as his hips dig into you. “that’s for lying. i know you’re not sorry one fuckin’ bit.” 

A wet tongue slides up the side of your face, then curls back down to trace the details of your ear. Distal phalanges run down your neck to your chest, leaving behind pink streaks of irritated skin. He jerks at the collar of your dress, popping a few seams, slipping behind your bra, yanking and tugging until both breasts bounce out. He cups one, pawing hungrily, then pinches an erect nipple.

“why don’t you be a good girl,” he breathes as the hand between your legs starts rubbing your wetness across your entire vulva, “and tell daddy the truth.”

The whimper you release is absolutely pitiful; he’s playing with you so roughly and all you can do is keep both hands on the graffitied wall for support. “You’re right,” you start, “I’m not sorry. I love teasing you. I want to see you get all flustered over me. I love knowing I have power over you.”

“mmmnnnnnn,” he rumbles, tongue returning to his mouth so he can plant soft, toothy kisses across your nape, “good start, babygirl. but that’s not enough.” He drops your heavy tit and curls that hand into your red locks, pulling until you crane around to face him. 

Open your mouth willingly when he offers his fingers, covered in your fluids. He’s shoving them inside, tickling the back of your throat. “get on your knees and suck my cock till i cum all over that pretty face of yours,” he says as he takes his hand back, wiping away the wetness on your bare chest, “then maybe i’ll forgive you and give you a reward.”

Immediately, you comply, crouching to avoid any bare skin touching the bathroom tile, panties ridding back up to your upper thighs. Curl your fingers around the waistband of his shorts and tug until his glowing, blue dick pops out. Let the material rest around the first divot of his ischial spine so you can take his thick member with both hands. Pull down the jelly-like foreskin and roll your tongue across the entire head, already tasting his precum.

“look at me, sweetheart,” he reminds you with a gentle tug to your hair. You do, putting on a little show as one hand moves to play with the bones of his spine and you take a mouthful of his length. Pull back, saliva adding shine, your hand using it as lube to jack off the base. Maintain eye contact the whole time. “ooh, good girl,” Sans sighs, stroking your locks as you start a steady rhythm.

The door to the bathroom creaks open. You freeze. Sans grins wickedly, gripping your scalp so you’re forced to take more of him. The patron goes into the neighboring stall, and based on the white paws, it must be Dogaressa. She does her business as you struggle not to gag or slurp, so afraid of getting caught. Sans takes your face in both hands and thrusts into you, silently admiring your look of anxiety. She washes her paws and the bathroom is empty again.

Uaagh, you pull back and cough, tears starting to stream down your face, adding to the drool lining your lips. He _tut-tuts_ you, petting your hair until you devour him again. Continue the frantic pace, not pausing when he starts face-fucking you. Then, without warning, he yanks your head back, phalanges choking his cock until it erupts with monster seed. It shoots once on your face, most of it landing on your tongue, the rest splatting down your chin and neck.

He’s still cumming, another jet of blue lands on the floor, but his grip on your hair tells you to stand up, so you do. Your front is pressed against the wall next to the toilet, dress flipped back up. Sneakers kick at your feet until you spread, hands knead and open your asscheeks, magical heat against your dripping cunt. 

A single slide of his still pulsing length up your folds, then he pauses. “ya want my cock, lil’ girl? beg for it.”

“Yes, Daddy,” you answer, “yes, I want your cock. Please, fuck me, **please.** ”

“good girl.”

Sans presses forward, entering easily with how wet and aroused you are. Your breath hitches and it takes everything in your power not to moan out loudly. It feels so GOOD. It’s thick and hot, stretching you perfectly, the remaining strands of cum are warm and almost tickling. Swallow down a noise and try to relax as he pushes and pushes until you’ve taken every inch.

“fuck yea,” he growls, pulling out, then plunging right back in with more force. He sets a swift pace right away, keeping most of his length burried, prodding that delicious spot deep inside you over and over. “you’re such a _freak_.” His muggy breath blasts across your shoulders and neck, a droplet of sweat leaving his skull to soak into the fabric of your dress. “so fucking wet for me. do you like being daddy’s lil’ girl?”

“Yes, Daddy!” you cry out, unable to contain yourself any longer. He feels so good and he’s all around you, his smell, his touch, his magic stimulating every inch of your body. “Please, fuck me harder!”

He obliges, ramming into your cunt, hand covering your mouth to muffle your screams. With each thrust, you’re pushed harder and harder into the wall, your tits flattened, sweaty skin sticking to the paint. Arch your back out a little more and you get that perfect angle, the base of his cock brushing your clit every time he hilts. Fuck yeah, fuck yeah, it’s so fast and hard, you’re getting close already.

Trembling and clawing at the wall, you mumble into his phalanges, “Daddy, sl-slow down, I’m gonna—“ That thought is lost when fingers replace his base on your clit, rubbing and running across it perfectly. His head nestles between your shoulder blades and he puts everything into fucking you, entire length out, back in, harder and harder until his pelvis feels like it’s bruising you.

“cum,” he demands, “ **cum** on daddy’s cock, babygirl.”

Instead of screaming out, you hold the orgasm inside, going silent as your cunt swells and heats to a new degree, exploding with sexual energy and cum. Your tunnel drums and quivers around him, mind clouding with feel-good neurotransmitters, your hips gyrating against his. Through the fog of your orgasm, you can feel his cock expand and pulse with his own release, filling you to the very brim.

For a while, he just lazily fucks you with short, slow thrusts, pushing his seed as deep as it can go while he catches his breath. You hum and reach back to hold him against you. When he’s satisfied, his member slowly pulls out and he yanks your underwear back up.

“lemme tell you what’s gonna happen,” he says as he nips softly at your flushed, sweaty body, “i’m gonna go back to my seat. you’re gonna make yourself look presentable and join me. we’re gonna have a nice meal. i’ll make a joke about the sandwich you order. we’re gonna have drinks and dessert. maybe take a romantic stroll by the river. and the whole time, you’re gonna keep my cum in this pussy. got it?”

Blink through the sexual sopor and attempt to answer, “yeeesss, Daddy. I’ll do my best.”

“good girl.” He pulls you off the wall, looking as normal as ever, not winded or bothered in the least. “and then i’m gonna take you home and ravage you all over again.”


	3. Fermata in the Air - Horror!Sans x Reader

**Summary for the Chapter:**

> Horrortale. Sans. Chains.

**Notes for the Chapter:**

> this was a commission. a fun one!
> 
> WARNING: THIS STORY IS DARK it contains **EXPLICIT NONCON/RAPE** , blood, cutting, horror, fearplay, death threats, vaginal sex, oral sex, magic, breeding kink, semen, multiple orgasms, bondage, kidnapping, uuh. i think that’s it. 
> 
> make sure you listen to the accompanying music!

[♫](https://www.youtube.com/watch?v=yfJAooq3mTg&feature=youtu.be&t=22m15s)

This place is hell. Literal hell. It’s like a Silent Hill game, except it’s full of deranged animals instead of disfigured humans. All you wanted to do was go home. It seemed like a simple request. But all this place kept throwing at you was puzzles. Puzzles and monsters and dead ends.

The tall skeleton with reddened teeth almost killed you. As you lay bleeding on the snow, he knelt and patted your head, calling you a good human. A human worth keeping. He brought you to his freezing cold garage. Put a collar around your neck, chained your arms to the wall. You were too weak to do anything other than cry. It was dark, he shoved something into your mouth, over and over again until you had to swallow it. It only tasted like blood to you, but it healed your wounds. He was disappointed that you didn’t thank him, but still gave you another gentle pat.

Maybe Papyrus wasn’t so bad. At least he wasn’t… at least he wasn’t his brother. His brother, a skeleton monster with a cracked skull and one gaping red iris that looked like some inhuman orifice, wide and torn. Fingers tap tap tapping on his stall, voice booming in his small frame. He’s scared you more than anyone so far. Unlike the others, he knew. He’s… aware of everything. And instead of trying to change it, he goes along with it. Maybe he just enjoys it.

Somewhere between the sound of snow beating at the window and the feeling of cold iron against your skin, you pass out. You didn’t have any dreams that you can remember. 

As you sleep, you hear a weird sound. Like a heavy piece of metal being dragged. _Scraaaaaape. Scraaaaaaaape. Scraaape. Thud._ The noise stops and you return to your restless slumber. 

Something touches you, but not jarringly enough to wake you. It’s warm and that alone makes you arch into it. It’s so warm and you want to let it embrace you. It does and in your sleep, you moan. This is nice. You think you could…

“AHH!!!” You SCREAM as something thick and hot forces itself between your legs, penetrating you instantly. Open your eyes, try to blink away the tears, to see who, what, **what’s happening!?!** Pull at your restraints, the metal jingling, a low, familiar chuckle. NO.

Sans’ glowing red eye gapes at you, casting the only light in the room, aside from whatever shining thing he’s shoving, ramming, pounding into your pussy, FUCK! He laughs again as you try to kick your legs, lurch away, do anything.

“c’mon, buddy,” he exhales, reeking of blood and bone rot, “no need to be such a DEAD WEIGHT.” He slams your head against the wall with the last two words, causing you to go limp with shock.

You’re dizzy, clenching and unclenching your hands, trying to breathe, and Sans never gives you a moment to recover. Through the static in your mind, you can hear the wetness of his cock sliding in and out of you, the creak of his bones, his panting.

He slows down, red eye never blinking, grin never faltering. You can feel the thickness of his shaft, the tip of his head as he pulls all the way out and goes back in. “feel that?” he rasps next to your ear, “you’re pretty fucking wet. why would a human enjoy any of this, huh?”

Instead of answering, you just shiver in his grasp and try to turn your head away. Sans hums and presses his damp teeth against your the pulsing veins in your neck. “Please, stop,” you whimper, his hands pulling your tits out as his cock just sits in you. 

He leans in and you can feel the power pulsate behind his magic eye. He kisses you and starts moving again, gentle at first, fluid thrusts, while planting soft nibbles against your lips. You make a small sound, maybe out of pleasure, you don’t know, but it makes him growl in response. Teeth sink into your bottom lip and pull until something rips. You SCREAM, swollen mouth now dribbling with red.

“do you wanna be a good human or a bad human?” he asks, voice strained as he fucks you.

“STOP,” you repeat, trying to sound powerful, but you have none. You have nothing.

“y’know what bad humans get, don’t you?” His jaw unhinges with a quiet creak, crimson tongue slithering out to lap at the torn flesh about your mouth. “they get,” he pauses to giggle, “they get _axed_ one final question: how do you wanna die?”

You don’t answer that.

Sans dips his head down to run his hot tongue across the blood pooling in your collar bone. “i wonder how i should kill you…” Groaning into you, he lets his dick pop out and you get a good look at it: thick, red, swollen, covered with your fluids. He laps at one exposed breast, flicking your erect nipple. You’re terrified he’s going to bite or rip it off, but he doesn’t. He’s being surprisingly gentle.

“i could just let you bleed you death,” he says with a sickening amount of sweetness as his warm hands caress both breasts. “maybe strangle you with your own hair.” You whimper at each harsh word and he responds with a light chuckle. This is all just a game to him, isn’t it?

His hand glides down your stomach and slips between your legs to your wet folds. A few fingers dip inside, feeling small compared to his huge cock. It feels nice. Why is he doing this? Why doesn’t he just fuck you, get it over with? Why does he have to make you like it? He finds that tender spot inside, making you shudder and moan.

“right there,” he asks playfully, “and here.” His thumb presses into your clit, another groan escaping your lips, spine unconsciously arching into him. Snivel and curl into yourself, the chains around your body jingling. He shooshes you as he goes even lower, tongue dipping into your navel before joining his fingers between your legs.

“maybe i’ll just E A T Y O U U P .” His teeth clamp shut, eyes gaping, you freeze, expecting him to bite your cunt clean off. Skelehands cup your ass and he takes your entire crotch in his mouth, teeth closing gently around you, tongue diving inside, rolling across your clit, lapping at your folds. It feels really good, only confusing you further, so many guttural emotions twisted inside, all you do is cry and accept it.

Sans eats you out with ravenous abandon, eyes lidded, seemingly getting lost in your taste and the movement of your body against his face. You look away, not wanting to watch— _**SHIINGGG**_ , he slams the blade of his axe into the mattress you’re lying on, the heavy metal colliding with the ground right next to you, a few sparks flying.

“don’t look away from me, kiddo,” he grumbles into your pussy, raising his axe to use the tip to aim your face back towards him. You just gape at him, trying not to look at the weapon, trying to ignore the small cut it left on your check. 

His swollen iris rolls up to you and he smiles, “good girl. will you cum if i keep doing this?” He punctuates the question with another jab of his tongue inside you. You nod in response. “maybe you should ask for it nicely.”

Lick at your swollen lower lip, the blood beginning to clot. His tongue and fingers won’t stop moving, constantly switching from pussy to clit to see what excites you the most. “Pl-…” you pause, the sound of your own voice almost startling you, “please, Sans.”

“please, what?” he asks, bringing his axe down your body, slowly, the edge leaving one long trail of split skin.

“Puuh-LEASE, make me cum!” you cry, so scared, so turned on, staring at the monster in horror as he brings you to climax. “Sa-Sans!!” Cum escapes around his fingers and into his mouth, but it’s all quickly replaced by his cock shoving into your still pulsating entrance. “Gaah, _fuuuuck_ ,” you sob, orgasm extended as the large insertion slides in and out, in and out. 

“good girl,” he hums, “so good. maybe i’ll keep you around for a little bit after all.”

Internally, you sigh with relief, but all your body can do is moan and spasm around him as he fucks you through your orgasm. 

Sans pants and lets his axe fall noisily to the floor, “it’d be a waste to kill such an obedient human.” Both his hands circle your hips and he lifts you up, ramming himself inside you at an inhuman speed. You whimper a few thank you’s, feeling yourself about to climax again. “but you still gotta pull your weight, buddy,” Sans huffs, “and it seems like you’re only good at one thing.”

He leans down, so his face is close to yours; can feel his breath on your skin, the trickle of monster sweat, the tickling of his fur-lined jacket. He says, “you’re gonna be my breeding bitch.”

 **WHAT?!** With renewed panic, you struggle, trying to close your legs, or at least stave off the orgasm cumulating in your body. Can he actually get you pregnant? Images of yourself bloody and swollen with child crowd your mind, building, each scenario more horrific than the last. “No,” you quiver, too stricken to grant your words any power.

His frantic thrusting slows so he can talk to you: “ain’t that a pretty picture?” he asks as he dips a finger in the long cut he left down your body, swiping the blood across your torso, “all heavy with my brood. tits huge and full with milk, fuck.” He growls at his own words, his dick throbbing inside you. 

Gory fingers move to your clitoris, the slightest touch making your cunt quake, which makes him laugh. “already? you wanna cum around my dick again?”

“NO!!” you scream, your body betraying you, grinding back against him, silently begging for more.

“yeaaa, say no louder, cry harder, lil’ bitch. i’m gonna,” he pauses briefly to catch his breath, “i’m gonna have so much fun breaking you. shit, i’m gettin’ close…” 

“Not inside,” you beg, “not inside, **please** , don’t cum inside me.”

“shuddap,” Sans hisses, slapping your tit, splashing blood in your face, “i’m gonna pump you full of cum over and over and over until you get pregnant. then y’know what i’m gonna do? i’m gonna fuck you s’more, filling you with every fucking drop of my cum.”

You thrash and cry and weakly kick your legs, yet you cunt still clenches, orgasm so close.

“mmmnn, you want that, don’t you, baby? i can feel your pussy, trying to milk me _dry._ you wanna be my breeding sow.”

You give up. Falling limp, letting the orgasm roll over you, genitals erupting with cum, muscles pulling Sans as close to your cervix as possible. So overwhelmed, mind clouded, you start grunting out ‘yes’ and ‘more.’

“that’s right,” Sans replies frantically, obviously close to climax himself, “you want my cum, don’t you? deep inside you, fuck **FUCK!** then take it, take it, you dirty lil human.” There’s warmth deep inside you as he unloads himself, so hot, so deep, your uterus throbbing to take in his seed. He praises you and pets your stomach as he continues thrusting, making sure every drop of monster cum sits inside. 

Through the sexual sopor, you can see the glow of his cum inside you, illuminating through the layers of fat and muscle, dull red igniting your lower stomach. Pussy sore, bleeding and chained, you curl into yourself and cry. Sans sprawls out next to you, taking deep breaths as he strokes your hair. He looks peaceful like that, almost harmless. 

His left eye opens, giant pupil focused on you, his grin, maniacal. “what do you wanna name it,” he asks. 


	4. The Summer Heat can Make You Crazy - UF!Sans x Reader

**Summary for the Chapter:**

> Poor sansy is in heat.

**Notes for the Chapter:**

> this was a commission. HEAVY BREEDING/IMPREGNATION KINK IN THIS.

He’s been acting weird all day. Weirder than normal. Sniffing, snorting, grunting, sweating, swearing. You know it’s ‘that time’ for him, but this is different. This could be dangerous. 

Not wanting to be cooped up with a carnally frustrated skeleton, you recommend a walk in the park. It’s a beautiful summer evening and maybe some fresh air will breathe some civility into those aching bones of his. 

The sun is about to set, leaving streaks of purple and pink across the sky. There’s a nice breeze, blowing through the leafs, making a soft sound. It’s overshadowed by the boisterousness of the park: kids, dogs, families, it seems like everyone had the idea to go out tonight. 

But even THAT is overshadowed by the grunting of your monster lover, each step, each breath, each movement making him groan. Poor thing. You try to hold his hand as you walk beside him, but it’s so slippery with sweat, you can’t get a good grip. He sneers at your attempt and pulls his hand away.

“What,” you ask, your hurt feelings obvious.

“stuff it, (your name). it’s yer fault i’m like this,” he snarls back, shoving both hands into the pockets of his shorts.

“ _Excuse me?_ What the fuck did I do?”

“iz day fourteen. i can smell it on ya.” He gets uncomfortably close, nudging his skull against the side of your face. “just released an egg. iz sittin’ in yer pretty lil fallopian tube right now, waitin’ fer me.”

Oh fuck. Ovulation. Your face flushes red and you stop dead in your tracks. Put a hand on your lower stomach, right above your womb, and glare at him. “That’s not my fault. I can’t control that.”

He lets his jaw open, a bit of drool running down his chin as his tongue manifests to lick at his upper teeth. “ya know how easy it’d be? ta knock ya up?”

“Sans, stop,” you hiss, looking around to make sure no one caught him saying that. A couple walking a few paces behind you laughs to themselves, then passes you in silence.

“ **w h a t** , “ he echoes in your brain, freezing reality for a split second before he exhales, red magic swirling between the spaces of his teeth.

Pause to collect yourself, taking a few steps away from him, already feeling slickness between your legs. Damnit. 

He snorts at the air loudly, like a wild hog, before licking his teeth again and stepping back into your personal space. “i can smell that, sweetheart,” he purrs, grabbing your upper arm roughly, fat bulging between his phalanges, “ya can’t hide from me. i bet i could bend ya over right here n’ ya’d cum all over my cock.”

“Fucker,” you snarl as you try to jerk away from him. He’s right but. but fuck that! He can’t just do this, he can’t have that much control over you. Especially not in public like this.

“that’s it,” he says lowly, fingers gripping until you squeal, “no other options now, sugartits. come with me.” With his hold on your arm, he pulls you into a nearby grove of pine trees. The sharp needles prick and tickle your skin as you stumble behind him, struggling to keep up with his frantic pace. God, what is he going to do? Is he going to fuck you out in the open?

Beyond the grove is a small clearing filled with thistle bushes, completely void of people, a lush virgin forest on the other side. Time and reality pause as he teleports both of you to the other side, deep within the trees. The only sounds are your breathing, the rustling of wind through the thick canopy above, and the quiet creak of the skeleton’s bones. You both look at each other. Blink once. Twice. And then he’s upon you.

A fluttering giggle escapes your mouth as his hands immediately go to your ass, pressing his crotch into you, his familiar erection already throbbing and ready. Lean your head back as he runs his teeth and tongue across your neck, feeling the need on him, smelling it in his musk, sensing the magic pulsing through his entire body.

“yer gonna be so pretty,” he rumbles into your skin, breath so hot, your hands reaching to take a hold of his jacket for stability, “all swollen and heavy with my babes.”

You whine at his words; he’s played around with the idea, but with this intense heat cycle, he really wants to impregnate you. Maybe this time he’ll actually do it. Filled with a slurry of fear and excitement, you remain as quiet as you can, but still give into every touch and lick.

“ya want that, dun’cha?” He dips between your breasts, fingers yanking and tucking until your chest is naked. 

“I-I don’t, uh” you trail off as he nuzzles his face into your tits and growls like an animal, mouthing at your flesh and nipples. Your pants are yanked down and he immediately grabs a handful of your wet panties.

“oooh, yes ya do. yer body doesn’t lie.” Phalanges slip behind the thin fabric, collecting your wetness and beginning to rub it up and down your folds. He sniffs at the air again, thrusting his erection into you, demanding attention.

Your dominant hand slides into his shorts to pull his cock out; it’s harder and hotter than you’ve ever felt, dripping so much precum that it’s staining his clothes. His fingers hasten, entering you, thumb diddling at your clit.

“tell me,” he says with a kiss, planting his wet teeth against your puckered lips, “tell me ya want my cum inside ya.” His own words fuel the fire, making him buck his dick between your legs, bumping his hand still ravaging your cunt.

“Oh, fuck, fill me, Sans,” you moan out, feeling release from saying the words alone. Finally, you’ve said it, the truth, your fingers clenching around him only for him to remove them.

“with _what?_ ” he asks as he teases your hungry entrance with the tip of his length, stroking up and down your wet crease.

“Your cum! Nnng, give me your gift, your seed, please! I need you now.” 

Panties ripped open, he grabs you by the thighs and slams you against the trunk of a tree, penetrating you immediately. It’s so big! He’s so hot, it throbs inside you once before he starts a breakneck pace, fucking you with a vigor you’ve never experienced before. You tits jiggle in his face as he just grits his teeth and fucks you, grunting and growling, completely focused on your pussy.

“GAAhaaaaaa FUCK,” you scream, uncaring of who might hear you, it already feels so good, the intensity of it overwhelming all your senses. You don’t notice the sun set or how badly the bark of the tree is splintering your back. “YES, SANS, **FUCK ME!** ”

There’s sudden, unbearable heat inside you as he abruptly climaxes. You cry out from the searing magic pumping against your cervix, grinding your hips down onto him, still too stimulated to care about anything other than him.

“yea, yeaaaa,” he almost whimpers, dropping his head to watch himself move in and out, pushing his seed as deep as it can go. “i’m gonna fill ya up sooo much, lil girl,” he pants, “yer mine, yer gonna be fuckin’ mine _ferever_.”

As you expected, he’s nowhere near done. He pushes your legs up to your torso, deepening the thrust of his cock, bumping your cervix each time. A hand curls around you thigh to rub your lower stomach.

“Mmm, Sans,” you whine, throwing your head back against the tree, following his eyes as he stares at your union, “I need more, feed my hungry pussy.”

“ooh, sweetheart. yer belly’s gonna get,” he pauses to strengthen the force of his cock impaling you, “so,” another, ”fuckin’,” and another, “ **BIG.** ” He pushes himself against you, crushing you between his ribcage and the tree, as his teeth nip at your neck.

All you can do is hang there in his arms, body not only enduring, but reveling in the relentless onslaught of pleasure and pain. He rips an orgasm from you, and you scream out loudly as your muscles pulse and dance around his cock, the intense release short circuiting your brain until all you can say is ‘Sans.’

“good girl,” he praises, “that’s my good lil (your name). ooh, oh fuck, i’m gonna pump you full of my pups, haaaah aah, so everyone knows yer mine. everyone will know who owns this pussy!”

After a few minutes of fucking you like that, he whimpers like a damn dog when he releases again, jet after jet of red cum firing into your womb. There’s so much, you can feel the liquid moving around inside you. He thrusts and mumbles incoherent things, grabbing your hips when he notices a few drops start to leak out, repositioning you so gravity assists in his endeavor to keep every bit inside.

Exhausted, the monster drops to his knees, carefully bringing you along with him. He pants heavily, tongue hanging out, sweat pouring, eyes closed, a strained expression on his face. His dick remains inside, still throbbing, no where near satisfied yet. Opening one eye socket, he looks at you and starts laughing.

“What,” you ask, trying to catch your breath as you lean back against the tree.

He gives you that stupid grin that you’ve come to love so much and says, “yer beautiful. i can’t believe ya actually exist. and that ya wanna be with me.”

Your hands find his face, wiping away a trail of sweat. And you kiss him. It’s soft, deep, and meaningful. A kiss that confesses all your feelings for him. All your love, desire, need. He whines and kisses back as best he can, moving his head and teeth along with you. It all instills new hunger in him, which you can feel through his cock drumming inside you.

Pull away to laugh at him a bit, he’s such a mess right now. He plants a toothy kiss on your forehead. 

“I’m actually going to get pregnant,” you say out loud, needing to hear it to solidify the fact, “I’m… I’m so happy! Thank you, Sans, for—…”

You trail off when he growls menacingly, gritting his teeth and getting an aggressive look on his face.

“roll over, hands and knees,” he commands, pulling you off him so you can do as he says. 

The soil is cold and coarse under your knees, but you’re so high off his pheromones, orgasms, and seed, you don’t even register it. Arch your back, pointing your ass at him invitingly and he completely loses his shit.

Frothing and snorting like a beast, he mounts you, swollen member sheathing itself in one fluid motion. Arms encircle you to keep you in place and his teeth sink into the skin of your shoulder, making you scream out in a mix of pain and pleasure. Growling into you, he fucks you like a dog, pistoning his cock in and out, in and out, all the way in, all the way out.

You throw your head back against him and let your mouth hang open, tits bouncing with each movement, drool trailing down your chin. Fingers dig at the soil beneath, dirtying your fingernails, filling the groves of your skin.

Sans laughs when you orgasm hard around his cock, teeth leaving your shoulder to carefully sink into the back of your neck. “sweeeeeetheeeaaart,” he drones, “how many pups do you think i can fit in you?”

You don’t respond with anything other than stilted moans and your hips bucking back against him.

“maybe four? fuck, yer gonna be so big. so full with my babies.” He chuckles again, so turned on, his own words make him throb and spurt a heavy wave of cum inside you. Sans fucks you through his climax, pumping you full of seed, so much, it’s so much, your stomach swells from the internal pressure.

You fall forward, ass still in the air, head resting on the grass as your lover’s magic and teeth leave you. He dips between your spread legs, tongue lapping at your pink, abused pussy. You whine and grind your hips back against him, the smell of blood and sex strong. 

“good girl…” he mumbles into you, “lookit how full you are.” His hand carefully rubs your distended tummy, and you look down to see it glowing, so much magic inside you that it illuminates through layers of fat and flesh.

He rolls you over onto your back and lovingly starts redressing you, pulling your torn panties up, buttoning your pants, working your breasts back into your bra. His tongue cleans the bite wounds and he feeds you a bite from a candy bar, healing you instantly.

You sit up, grumbling, feeling your stomach rumble from the amount of cum inside.

Sans gives you that same stupid grin, asking, “think ya can be a good lil human and keep all my seed inside you?”

“Yeeeessss, Sans,” you purr, reaching to plant a kiss on his toothy face.

“ya can call me _daddy_ ,” he chuckles. 


End file.
